20 CFR § 211.2 - Definition of compensation.
(a) The term compensation means any form of payment made to an individual for services rendered as an employee for an employer; services performed as an employee representative; and any separation or subsistence allowance paid under any benefit schedule provided in conformance with title VII of the Regional Rail Reorganization Act of 1973 and any termination allowance paid under section 702 of that Act. Compensation may be paid as money, a commodity, a service or a privilege. However, if an employee is to be paid in any form other than money, the employer and employee must agree before the service is performed upon the following:
(1) The value of the commodity, service or privilege; and
(2) That the amount agreed upon to be paid may be paid in the form of the commodity, service or privilege.
(b) Compensation includes, but is not limited to, the following:
(1) Salary, wages and bonuses;
(2) Pay for time lost as an employee;
(3) Cash tips of $20 or more received in a calendar month;
(4) Vacation pay;
(5) Military pay as determined in § 211.7 of this part;
(6) Displacement allowances as provided for in § 211.8 of this part;
(7) Dismissal allowances as provided for in § 211.9 of this part;
(8) Separation allowances as provided for in § 211.10 of this part;
(9) Miscellaneous pay as provided for in § 211.11 of this part;
(11) Payments paid to an employee or employee representative which are subject to tax under section 3201(a) or 3211(a) of the Internal Revenue Code of 1954 are creditable as compensation under the Railroad Retirement Act for purposes of computation of benefits under sections 3(a)(1), 3(f)(3), 4(a)(1) and 4(f)(1).
(c) Compensation does not include:
(1) Tips, except as provided in paragraph (b)(3) of this section;
(2) Payments for services performed by a nonresident alien for the period the individual is temporarily present in the United States as a nonimmigrant under subparagraph (F) or (J) of section 1101(a)(15) of title 8, U.S.C. and which is performed to carry out the purpose specified in subparagraph (F) or (J), as the case may be;
(3) Remuneration paid in certain cases, as described below, for services performed for a local lodge or division of a railway labor organization.
(i) Remuneration for services rendered for a local lodge or division of a railway labor organization which was earned after 1936 and prior to April 1, 1940, shall not be creditable as compensation in a month unless taxes with respect to such remuneration were paid under the Railroad Retirement Tax Act prior to July 1, 1940.
(ii) Remuneration for services rendered for a local lodge or division of a railway labor organization which was earned after March 31, 1940, and prior to January 1, 1975, shall not be creditable as compensation in a month if the amount of such remuneration earned in the month is less than $3.00.
(iii) Remuneration for services rendered for a local lodge or division of a railway labor organization which was earned after December 31, 1974, shall not be creditable as compensation in a month if the amount of such remuneration earned in the month is less than $25.00.
(4) Payments for service as a delegate to a national or international convention of a railway-labor-organization employer if the individual rendering the service has not previously rendered service, other than as a delegate, which may be included in the individual's years of service;
(5) Except as provided in § 211.2(b)(11), the amount of any payment (including any amount paid by an employer for insurance or annuities, or into a fund, to provide for any such payment) made to, or on behalf of, an employee or any of the employee's dependents under a plan or system established by an employer which makes provisions for employees generally (or for employees generally and their dependents), or for a class or classes of employees (or for a class or classes of employees and their dependents), on account of sickness or accident disability, or medical, or hospitalization expenses in connection with sickness or accident disability; and
(6) Any amount paid specifically - either as an advance, as reimbursement or allowance - for traveling or other bona fide and necessary expenses incurred, or reasonably expected to be incurred in the business of the employer, provided the payment is identified by the employer either by a separate payment or by specifically indicating the separate amounts where both wages and expense reimbursement or allowance are combined in a single payment.